This file shows land area flooding at the tract level and county for the state of Georgia. It also pulls out tract locations of high flooding as well as their subsequent counties. It then multiplies tract social vulnerability indicator percentiles by flooding proportion to create a flooding-vulnerability, which is also interactively mapped. Finally, a comparison is drawn between flooded FEMA community lifelines and area flooded by county.
The datasets are the National 100-year flood layer (2018), CDC SVI indicators (2018), and Re-Public’s database of flooded community lifelines (accessed December 2020).
These estimates show that as a result of a 100-Year flood (ignoring pluvial flooding), Georgia is 14.86% flooded by land area (which likely includes wetland areas as well). Coastal counties face the brunt of flooding (up to 60% of land area flooded), though the southeastern corner of Georgia as well as various inland tracts also have high risk.
Assuming nearly 15% is also an estimate for population impacted by flooding, around 1.5 million people could be affected (out of the over 10M people residing in Georgia now).
The datasets include 1966 tracts, 1960 of which are mapped. Of those 1966, 117 have null values for flood data. We assume that in the case of missing flood data, the % tract flooded is 0, and have replaced null values with 0.
The following plot shows tract-level land area flooding.
This plot shows the relative population affected (using % flooding as the proportion for population affected).
These following table outlines a list of tracts with flooding close to or above 50%.
| LOCATION | CensusTractSubmergedInFlood | geometry |
|---|---|---|
| Census Tract 9900, Liberty County, Georgia | 100.000 | MULTIPOLYGON (((-81.194 31…. |
| Census Tract 9900, McIntosh County, Georgia | 100.000 | MULTIPOLYGON (((-81.26668 3… |
| Census Tract 106.01, Dougherty County, Georgia | 97.789 | MULTIPOLYGON (((-84.17031 3… |
| Census Tract 111.08, Chatham County, Georgia | 96.465 | MULTIPOLYGON (((-80.97446 3… |
| Census Tract 9, Glynn County, Georgia | 94.596 | MULTIPOLYGON (((-81.49668 3… |
| Census Tract 115, Chatham County, Georgia | 89.436 | MULTIPOLYGON (((-81.24293 3… |
| Census Tract 1.01, Glynn County, Georgia | 89.077 | MULTIPOLYGON (((-81.4026 31… |
| Census Tract 111.03, Chatham County, Georgia | 86.990 | MULTIPOLYGON (((-80.93591 3… |
| Census Tract 111.07, Chatham County, Georgia | 86.810 | MULTIPOLYGON (((-81.0481 32… |
| Census Tract 8, Glynn County, Georgia | 84.995 | MULTIPOLYGON (((-81.52685 3… |
| Census Tract 4.03, Glynn County, Georgia | 84.723 | MULTIPOLYGON (((-81.4637 31… |
| Census Tract 111.09, Chatham County, Georgia | 84.652 | MULTIPOLYGON (((-81.00881 3… |
| Census Tract 110.04, Chatham County, Georgia | 81.443 | MULTIPOLYGON (((-81.09841 3… |
| Census Tract 101.01, Chatham County, Georgia | 81.036 | MULTIPOLYGON (((-81.08505 3… |
| Census Tract 108.07, Chatham County, Georgia | 79.811 | MULTIPOLYGON (((-81.28884 3… |
| Census Tract 108.06, Chatham County, Georgia | 78.148 | MULTIPOLYGON (((-81.23218 3… |
| Census Tract 1103, McIntosh County, Georgia | 76.678 | MULTIPOLYGON (((-81.27939 3… |
| Census Tract 3, Glynn County, Georgia | 75.808 | MULTIPOLYGON (((-81.42155 3… |
| Census Tract 2, Glynn County, Georgia | 74.389 | MULTIPOLYGON (((-81.4131 31… |
| Census Tract 111.06, Chatham County, Georgia | 74.253 | MULTIPOLYGON (((-81.04864 3… |
| Census Tract 9508, Ware County, Georgia | 73.418 | MULTIPOLYGON (((-82.66664 3… |
| Census Tract 109.01, Chatham County, Georgia | 72.065 | MULTIPOLYGON (((-81.21253 3… |
| Census Tract 110.05, Chatham County, Georgia | 70.939 | MULTIPOLYGON (((-81.10729 3… |
| Census Tract 9800, Bryan County, Georgia | 68.138 | MULTIPOLYGON (((-81.76334 3… |
| Census Tract 101.02, Chatham County, Georgia | 66.918 | MULTIPOLYGON (((-81.06745 3… |
| Census Tract 9203.01, Bryan County, Georgia | 66.888 | MULTIPOLYGON (((-81.40496 3… |
| Census Tract 5.03, Glynn County, Georgia | 66.376 | MULTIPOLYGON (((-81.48287 3… |
| Census Tract 106.05, Chatham County, Georgia | 66.081 | MULTIPOLYGON (((-81.09853 3… |
| Census Tract 101.01, Liberty County, Georgia | 65.873 | MULTIPOLYGON (((-81.67059 3… |
| Census Tract 9203.05, Bryan County, Georgia | 64.588 | MULTIPOLYGON (((-81.32112 3… |
| Census Tract 1, Chatham County, Georgia | 64.440 | MULTIPOLYGON (((-81.1124 32… |
| Census Tract 105.01, Liberty County, Georgia | 64.253 | MULTIPOLYGON (((-81.42268 3… |
| Census Tract 101, Charlton County, Georgia | 64.178 | MULTIPOLYGON (((-82.4156 31… |
| Census Tract 106.02, Camden County, Georgia | 62.741 | MULTIPOLYGON (((-81.53934 3… |
| Census Tract 102.07, Liberty County, Georgia | 62.336 | MULTIPOLYGON (((-81.65056 3… |
| Census Tract 113, Dougherty County, Georgia | 61.847 | MULTIPOLYGON (((-84.17697 3… |
| Census Tract 303.05, Effingham County, Georgia | 61.253 | MULTIPOLYGON (((-81.23441 3… |
| Census Tract 1305.03, Forsyth County, Georgia | 60.914 | MULTIPOLYGON (((-84.04108 3… |
| Census Tract 106, Liberty County, Georgia | 60.731 | MULTIPOLYGON (((-81.60794 3… |
| Census Tract 1102, McIntosh County, Georgia | 60.441 | MULTIPOLYGON (((-81.44781 3… |
| Census Tract 104, Liberty County, Georgia | 60.437 | MULTIPOLYGON (((-81.6144 31… |
| Census Tract 14.03, Dougherty County, Georgia | 60.239 | MULTIPOLYGON (((-84.17652 3… |
| Census Tract 104.02, Camden County, Georgia | 59.231 | MULTIPOLYGON (((-81.66717 3… |
| Census Tract 206, Houston County, Georgia | 58.750 | MULTIPOLYGON (((-83.61932 3… |
| Census Tract 9702, Long County, Georgia | 57.850 | MULTIPOLYGON (((-81.83838 3… |
| Census Tract 111.04, Chatham County, Georgia | 57.643 | MULTIPOLYGON (((-80.9921 32… |
| Census Tract 110.06, Chatham County, Georgia | 57.088 | MULTIPOLYGON (((-81.06405 3… |
| Census Tract 106, Richmond County, Georgia | 56.938 | MULTIPOLYGON (((-82.00507 3… |
| Census Tract 105, Camden County, Georgia | 56.927 | MULTIPOLYGON (((-81.57688 3… |
| Census Tract 139, Bibb County, Georgia | 55.873 | MULTIPOLYGON (((-83.67269 3… |
| Census Tract 42.09, Chatham County, Georgia | 55.710 | MULTIPOLYGON (((-81.13761 3… |
| Census Tract 9203.06, Bryan County, Georgia | 55.257 | MULTIPOLYGON (((-81.35657 3… |
| Census Tract 115, Muscogee County, Georgia | 54.743 | MULTIPOLYGON (((-84.98697 3… |
| Census Tract 101.02, Liberty County, Georgia | 54.406 | MULTIPOLYGON (((-81.8244 32… |
| Census Tract 9702, Clinch County, Georgia | 54.357 | MULTIPOLYGON (((-82.9707 30… |
| Census Tract 33.02, Chatham County, Georgia | 54.028 | MULTIPOLYGON (((-81.13544 3… |
| Census Tract 105.02, Liberty County, Georgia | 53.066 | MULTIPOLYGON (((-81.51645 3… |
| Census Tract 1305.05, Forsyth County, Georgia | 52.638 | MULTIPOLYGON (((-84.07272 3… |
| Census Tract 304.01, Effingham County, Georgia | 52.541 | MULTIPOLYGON (((-81.4186 32… |
| Census Tract 108.01, Chatham County, Georgia | 52.521 | MULTIPOLYGON (((-81.34667 3… |
| Census Tract 10, Glynn County, Georgia | 52.173 | MULTIPOLYGON (((-81.78249 3… |
| Census Tract 106.01, Camden County, Georgia | 52.130 | MULTIPOLYGON (((-81.58762 3… |
| Census Tract 1.02, Glynn County, Georgia | 51.663 | MULTIPOLYGON (((-81.42259 3… |
| Census Tract 108.08, Chatham County, Georgia | 51.114 | MULTIPOLYGON (((-81.30383 3… |
| Census Tract 1305.04, Forsyth County, Georgia | 50.288 | MULTIPOLYGON (((-84.10237 3… |
| Census Tract 15.02, Hall County, Georgia | 49.376 | MULTIPOLYGON (((-84.06225 3… |
| Census Tract 9701, Long County, Georgia | 48.778 | MULTIPOLYGON (((-81.98162 3… |
| Census Tract 5.01, Glynn County, Georgia | 48.495 | MULTIPOLYGON (((-81.4925 31… |
| Census Tract 15.01, Hall County, Georgia | 48.436 | MULTIPOLYGON (((-83.98399 3… |
| Census Tract 104.03, Camden County, Georgia | 47.634 | MULTIPOLYGON (((-81.6593 30… |
This dataset includes the flooded area by county, calculated by summing tracts by county.
| COUNTYFP | county_flooded |
|---|---|
| 051 | 59.708367 |
| 179 | 58.024741 |
| 191 | 57.640672 |
| 029 | 56.550479 |
| 127 | 52.415600 |
| 299 | 52.302681 |
| 183 | 51.330375 |
| 049 | 49.601626 |
| 065 | 49.177023 |
| 039 | 45.503681 |
| 075 | 32.906556 |
| 095 | 26.441298 |
| 025 | 25.601968 |
| 103 | 23.813306 |
| 173 | 23.772350 |
| 181 | 22.844594 |
| 253 | 21.967847 |
| 229 | 20.822343 |
| 001 | 19.901261 |
| 021 | 19.490464 |
| 235 | 18.293711 |
| 267 | 17.838891 |
| 037 | 17.755408 |
| 271 | 17.483767 |
| 007 | 17.269310 |
| 031 | 17.150642 |
| 251 | 17.033070 |
| 129 | 16.857576 |
| 027 | 16.195223 |
| 205 | 16.066551 |
| 165 | 16.045831 |
| 071 | 15.611222 |
| 245 | 15.528148 |
| 101 | 14.979588 |
| 319 | 14.802538 |
| 209 | 14.531650 |
| 309 | 14.348986 |
| 305 | 14.152479 |
| 099 | 13.809162 |
| 047 | 13.546721 |
| 279 | 13.410809 |
| 117 | 13.329940 |
| 193 | 13.317430 |
| 061 | 13.270571 |
| 153 | 13.146230 |
| 285 | 12.965847 |
| 113 | 12.656078 |
| 147 | 12.510027 |
| 109 | 12.502574 |
| 315 | 12.478689 |
| 297 | 12.471795 |
| 087 | 12.380623 |
| 275 | 12.140745 |
| 139 | 12.088594 |
| 115 | 11.948528 |
| 069 | 11.761688 |
| 081 | 11.686528 |
| 211 | 11.677079 |
| 003 | 11.660754 |
| 239 | 11.651995 |
| 289 | 11.643400 |
| 019 | 11.298666 |
| 175 | 11.065599 |
| 177 | 11.007648 |
| 105 | 10.966073 |
| 201 | 10.861332 |
| 009 | 10.808063 |
| 151 | 10.806753 |
| 257 | 10.719266 |
| 215 | 10.719166 |
| 013 | 10.490497 |
| 277 | 10.355827 |
| 161 | 10.194614 |
| 313 | 10.099054 |
| 155 | 10.022441 |
| 217 | 9.845303 |
| 185 | 9.799537 |
| 035 | 9.792955 |
| 255 | 9.770228 |
| 015 | 9.602915 |
| 131 | 9.584028 |
| 149 | 9.446411 |
| 043 | 9.354382 |
| 067 | 9.265948 |
| 077 | 9.212994 |
| 213 | 9.188935 |
| 097 | 9.068126 |
| 091 | 8.799428 |
| 259 | 8.796006 |
| 033 | 8.562536 |
| 063 | 8.526302 |
| 163 | 8.501753 |
| 133 | 8.485584 |
| 145 | 8.380333 |
| 321 | 8.334257 |
| 157 | 8.306350 |
| 273 | 8.194701 |
| 199 | 8.154257 |
| 107 | 8.110432 |
| 005 | 8.079400 |
| 057 | 7.851694 |
| 053 | 7.795325 |
| 073 | 7.765448 |
| 045 | 7.734566 |
| 303 | 7.703149 |
| 237 | 7.674094 |
| 059 | 7.643775 |
| 283 | 7.609106 |
| 089 | 7.511902 |
| 247 | 7.388975 |
| 269 | 7.346512 |
| 287 | 7.330606 |
| 121 | 7.253732 |
| 189 | 7.227328 |
| 291 | 7.160038 |
| 135 | 7.140461 |
| 167 | 7.131982 |
| 079 | 7.099950 |
| 307 | 7.077943 |
| 093 | 7.047966 |
| 265 | 7.022541 |
| 055 | 6.953729 |
| 261 | 6.839159 |
| 125 | 6.666187 |
| 233 | 6.642979 |
| 221 | 6.641154 |
| 017 | 6.615973 |
| 219 | 6.575371 |
| 293 | 6.513151 |
| 227 | 6.271363 |
| 263 | 6.246222 |
| 111 | 6.157145 |
| 011 | 6.047913 |
| 083 | 5.940659 |
| 231 | 5.736202 |
| 143 | 5.411986 |
| 023 | 5.353882 |
| 171 | 5.317345 |
| 195 | 5.268399 |
| 123 | 5.249603 |
| 317 | 5.228024 |
| 085 | 5.152320 |
| 281 | 5.085194 |
| 225 | 4.881617 |
| 169 | 4.807240 |
| 241 | 4.793756 |
| 223 | 4.694916 |
| 243 | 4.096941 |
| 295 | 4.019698 |
| 141 | 3.720443 |
| 249 | 3.653027 |
| 207 | 3.596875 |
| 301 | 3.521671 |
| 137 | 3.439232 |
| 311 | 2.976795 |
| 187 | 2.761211 |
| 159 | 2.630136 |
| 197 | 2.271280 |
| 119 | 2.191250 |
The interactive plot below includes county names and subsequent flooding.
Looking specifically at our 7 counties of analysis: Chatham: 59.708% flooded; Liberty: 58.025% flooded; McIntosh: 57.641% flooded; Stewart: 8.796% flooded; Colquitt: 15.611% flooded; Rabun: 4.794% flooded; Whitfield: 10.099% flooded
Using Re-Public community lifeline flooding data at the county level, we wanted to assess the relationships between land area flooded and lifeline flooding. Outliers in particular may give an indication of which counties have more pressing mitigation needs related to critical infrastructure, and a relationship between both would encourage more robust flood area analysis and hazard mitigation planning.
There is little correlation between the two parameters (R^2 = 0.08651). While there are 119 points not labeled, those points come in the center. We are especially interested in the outliers, especially ones experiencing high land area flooding or high lifeline flooding. While some of the coastal counties face very flood risk by land area, inland counties with high social vulnerability (ex. Colquitt) may deal with a large loss of critical infrastructure.
##
## Call:
## lm(formula = county_flooded ~ lifelines_impacted_ratio, data = GA_county_flooding_lifelines)
##
## Residuals:
## Min 1Q Median 3Q Max
## -19.105 -5.712 -2.400 0.591 42.999
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 3.924 2.516 1.560 0.120867
## lifelines_impacted_ratio 43.423 11.256 3.858 0.000167 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 11.2 on 157 degrees of freedom
## Multiple R-squared: 0.08658, Adjusted R-squared: 0.08076
## F-statistic: 14.88 on 1 and 157 DF, p-value: 0.0001667
Social Vulnerability Indicators and Flooding
For every tract, we calculated a combined social vulnerability-flooding score by multiplying the vulnerability percentile (ranked at the state level) with the tract flooding. This was done for the overall vulnerability percentile, socioeconomic vulnerability percentile, household composition vulnerability percentile, language isolation vulnerability percentile, and housing structure vulnerability percentile.
Below is a table that includes the top 10 most “vulnerable” tracts based on overall flooding and SVI rankings.
This graphic shows the scores from the overall vulnerability percentile.
This graphic shows the scores from the socioeconomic vulnerability percentile.
This graphic shows the scores from the household composition vulnerability percentile.
This graphic shows the scores from the language isolation vulnerability percentile.
This graphic shows the scores from the housing structure vulnerability percentile.